dougeff wrote:
1.Language is fluid, not static
2.If a word is used, and you understand its meaning, it is being used properly
In general I try to avoid engaging in pointless arguments about definition, but there is one big exception:
If you are writing didactic text, or reference material, it is worth debating what words mean so that you can choose words that express the ideas accurately and clearly. Ironically, this exception tends to come up a lot when maintaining a
wiki.

In conversation, however, you're trying to communicate an idea to one or more people. If they get it, you've succeeded. I think it's generally impolite to point out someone's impure/loose choice of word unless you were
actually confused by it (or honestly believe someone else in the conversation is), or in a rarer case if you know they are learning the language and wish to have their mistakes corrected. It's pretty much an identical situation to pointing out someone's spelling mistakes.
Sometimes it's fun to talk about what words mean, though, but that's best done as its own conversation (like this thread), otherwise it's often an impolite digression.
Also, if you'd like to be tactful you can feign confusion: "Which Wiki was it on?" vs. "You should have said Wikipedia."
Usually attempting to understand the idea someone is trying to express results in a healthier conversation than criticizing the way they tried to express it.
